Text doesn't show up in zoomed section
Ok so seems blender's interface is a bit unintuitive for newcommers, because after I put the text strips to the top, the main strips at the bottom and the effect strips in the middle, everything worked perfectly and as expected.

You really have to keep in mind the order (top to bottom) of your strips since they determine the layering of your, I guess, masks? It is also important which effects are applied to which strip, because similarly my speed effect (speed to zero for a freeze frame) didn't work with my transform if I applied both to the main sequence.

So top to bottom order and effect attribution are pitfalls as far as I can tell.